Die-casting machine



N. LESTER DIE CASTING MACHINE June 19, 1928.

June 19, 1928. l

K N. LESTER v 5 Sheets-Sheet 2 vaoz `:M q

DIE 'CASTING MACHINE F 1ed Deo. 22, 1926 `une 19, 1928.

N. LESTER DIE CASTING MACHINE i Filed Deo. 22, 1926 5 Sheets-Sheet June19, 1928.

N. LESTER DIE CASTING MACHINE Filed Dec. 22, 1926 5 Sheets- Sheet 4 June19, 1928-.

N. LESTER DIE CASTING MACHINE 5 Sheets-Sheet '5 Filed Deo. 22, 1926 JDJ707 Jog joa ratentecl June 19, 1928.

. `NATHAN' LESTER, OF WORCESTER, MASSACHUSETTS.

DIE-CASTING MACHINE. i

Application led IIJeceinber 22, 1926. Serial No. 156,477..

This invention relates to a machine forA castlng metals' ijn metalmolds, known as dles.

The principal vobjectsfoi the invention are to provide a separable dieof the ordinary type with means for opening and closing it, preferablyunder oil pressure, and with means whereby when the die is -opened thecasting will be ejected by the die operating l0 means; to providecontrolling mechanism by l which the proper sequence of operations islvcaused to take placewithout any attention Ion the part of the operatorexcept to turn a'lever for opening and closing the dies and'.

' 'another lever. for .operating the pump; toi

construct the mechanism for performing the -v Vtwo operations 'in'such-a Way that the-operator cannot turn either handle vat the wrongtime and that the metal cannot be forced out of the pump v.unless themold is closed and forced up to casting position; to provide meansoperatedby the die operatmg mechanism for moving the pump in the meltingpot Orladle up to the position for Vcasting andv making sure that, thesame is in i that position before the metal is forced into the mold; toprovide a casting pump in which the nozzle will move withthe pumpV.accurately toentr the sprue in sucha way a0 as ,to prevent theformation of a projection on the cast .metal that would prevent orinterfere with the removal of the casting;

to provide'a movable pump'no'rmally sub-v` merged in the metal in thecasting pot when a5 vnot in casting position-for the purposeofkeeping itheated and iilling it with metal; to provide an air operated pump with amete al ejecting nozzle and an air receiving'noz-- zle, so related thatthey will both come simultaneously into proper position to conneet thepump with its air supply and the dies; to providemeans for ,cooling thesta-` tionarygland ofthe` mold, which really constitutes the sprue,'inorder to prolong the' life of this important element, and to provideimprovements in the mechanisms and various Vfeaturesof construction incarrying out these objects.

Reference'is to be had to the accompanying drawings in which Fig. 1is aside View of a complete diecasting machine constructed in accordancewith this invention; g

Fig. 2 is a plan o'means for controlling the admission of power fluidtothe cylinder treme positions; f

or throughthe frame. to provide for dies of dierentthickness.

PATENT OFFICE.

which operates the dies and air tothe pump;

Fig.` 3 is a side view of ,the connecting parts between the dieoperating means and Pump;

Flg. 4 1s an end view ofthe same; 60 Fig. 5 is asectio'nal view' on theline5-5 ofF1g.3; v v Figs 6 and 7 are enlar ed views ofthe die operatingmechanism siown intwo .ex-

Figs. 8 and 9 are sectionalviews on .the v linesv 8-8 and 9,-9respectively of Fig; 7;

vFig. 10 is an yenlarged `side view of the pump and its actu-atingmechanism;

v Fig. 11 is a 'front elevation on'enlarged 10 .Y scale of the frontmold wall showing the lair connectlons at this point and the waterdevice above mentioned; and .I

Figs. 15, 16 and 17 are views of the cams which control the operation ofthe rpump and dies, shown in three different positions.

Referring first to the first three sheets of drawings, whichillustrateparticularly the die operating mechanism, it will be seen that4the-machine embodies a frame'l() carryin a stationary vertical plate 11against'whic one of the'dies 12 is adapted tojbear and l a slidableavertical plate V13 carrying the other die 14 with it. There is `alsof@`sta- "9'0 tionary end piece 15|whichf1s mountd'cn ways on the, bed orlframe 10 and is adjustable therealong by bolts extending into i The`adjustment vis e .05 This end plate 15 is securedto the endplate 11;,bythreaded horizontal rodsv 16. The plate 13 has a' slide or base 19extending to the rear adapted to slide on the ways 18 at the top of thispart of the frame '10. 100 Supported by the end plate 15 is a cylinder20 within whichis a piston 21 provlded with a piston 'rod 22 whichcarries a'sliding rack 23 which yis of a double character as it hasrackteeth on its opposite sides. This rack is adjustedon the` rod`bymeans of screw andA nut connection 24 and it lsprovided ided in .vrying studs 28on oppoffite sides of the rack.

On each of the pivot studs'is pivoted a gear Se ment 29.meshing with oneof the racks. Flxed to'each segment is an arm 3() which swings withthe...gear segment and is connected by a lever 38 with a link 39 pivotedthereto and also pivoted on a projection on the movable plate 13. Theselevers 38 and arms 39 are provided with projections 40 and 41 which,when the parts are in the extreme position shown in Fig.l 7, abutagainst each other and prevent the link andl lever constructions frompassing beyond the dead center, thus limiting the action. The levers 38are pivoted, it will be obvious, at one end to the arms 30 and to thelink 39 at the opposite end. In the middle they are pivoted to a' head42 which is arranged to move longitudinally butat a different rate vofspeed from the rack 23. This will be obvious from the eimncctions Lhewnin Figs. 6 and 7. This head is provided with a pair of ejectors 43 inthe form of rods or'plates. While in casting position, these ejectorsproject 'beyond the plate 13 into spaces in the die 14 and extend clearto the casting face of the vmold cavity of which their ends constitute apart.i l/Vhenmoved Th from the position shown in Fig. 7, 'to that shown.1n Fig. 8, these rods eject a casting. This ejection is due to the factthat, on aecount of the leverage, the die 14 is retracted fasterthan thehead 42 and ejectors 43.

The cylinder' and plunger 21 which are used for operating the diesection 14 and the ejection of the castin is intended to be operated byany kind o fluid but I have by oil. The oil is furnished by shown hereina mechanism for yoperating it d an oil pump 43, the detalls of which arenot shown, but 1t dellvers and discharges through two pipes 44 and 45 toa valve casing 46 an'd is so `constructed 'that the oil in these pipesis under pressure all the time while the oil ump is running. In thiscasing 46 there are valves, mounted on a shaft 50, which control thepassage of oil from the j and 48 which lead 1nto the opposite ends ofthe cylinder 20.

'It will be obvious that inaccordance with the operation of these valvesthe oil will be admitted to one end or the other of the cylinder-andforce the pistonback or forward.

- This cylinder itself has no valves', being controlled entirely by thedirection of flow of the operating liquid.` The valves 1n the easing 46are located on the shaft 50 which pipes 44 and 45 re? spectlvely to twopipes 4 19. Mounted on brackets 53 on the frame 10 is a shaft 54carryinga gear 55 meshing with the rack 52. On this shaft 54 1s a crank56 which is connected with a rod 57.

Theereciprocation of the rack v52 causes the gear to oscillate and therod 57 to be moved back and forth. This rod is provided with anadjusting screw 58 meshing with a rack 59 cut on the surface of a link60 which is in turn connected with an larm 61 for a pur B5 pose to bedescribed. It will be seen therefore that the reciprocation of thedouble rack 23 by means of the piston in thecylinder opens and closesthe die and ejects the.

casting therefrom and further operates Ithis arm 61 to swing it aboutits axis. This arm 61 operates the pump to lill the dies as will appear,below.'

The pumping means for this machine comprises a melting furnace 62,preferably on the frame 10, having therein a melting pot 63 in =which asupply of metal is maintained.

e pump is operated by air pressure controlled from a handle or lever 64fixed on a shaft 68 which handle is located near the handle 51 so thatthe operator can attend to both of them. The shaftv 68 extends to thepump and is provided with two cams or eccentrics 73 and 74 which operatevalves in'a valve casing 77 to control the'connection'of the pump withtwo pipes 75 and 76 which, as will be described later,.exert presure onthe metal in the pump to force it vinto the mold at certain times. d Onthe'controlling shaft 50 is a cam 66. This cam is of circular shape. allaround except for a notch 67 at one point. On the shaft 68 below thereis another cam 69 which 1s of general circular form but also with anotch 70 of the same size and shape as the notch 67. Each of.these'notches, as will be 'observed from comparison of Figs. 15, 16

and '17, is of such shape that the other earn can rotate when inregistratlon with that notch but not otherwise. Each notch 1s of 'theshape of anarc of the circle ofthe other cam. The .shafts 50 and 68 havetheir axes at a distance apart less, by thewidth of one of thevnotches,than the sumof the radn of the two cams. o I

' In the position shown 1n Fig. 16, elther cam can be turned from itsposltion, but 1n the positions shown in Figs. 15 and 17 only vone camcan turn. The cam 69 also has another notch 71 which vcooperates withl apin 72 to constitute a stop. This cam' oscillates the length of `t-hisslot andv cannotl 'move beyond it.' The valves 73 and 73.- connect theair`inlet 75 v vith the pipe` 76when the cam`74 closes its valve andthecam,7 3

opens the other valve.

The'control of the air to the pump and the control of the `oil tothe-operating cylinder are both manual.` The latter, as stated above,

actuates the arm 61- which is located ona.

g shaft 91. This shaft is mounted on a base 83 which isprovided withWays below and is l zo capable of aslight sliding motion.` This is animportant't'eature, becausel it is secured by longitudinal rod 84 to thestationary plate 11. Orhaccount of the expansion ofthe metal of whichthe parts are made under the influence of heat and the .subsequentcontraction, some ofthe meta-l parts would break. rIhe support 83ismounted in this vvay so that it can moveback and forth, but

v of course it Will be understood that `,this is through the nozzle. .Itissupported byja :in link 90 which depends therefrom andis'co nectedwith the stud 86 so as tov support o f by a bolt 94.

a '103, under which extends the endsjofa '.larhpfthe pump 'toi moverectilinearly gland '111v which`isprovidedfwithfavvate circulatinggrtmve 112z appliediin anyde'sire "Way t0 keep this glnde, -Y life.`n'thefurnaceis`gi1''stu' i l suitable [bearings andlcarry ingaL-...fpla

`by abolt for holdingvthe'lcove 106 passage 107 and a nozzle 108.31vThisl only a slight movementin accordance with 2f the temperature oftheparts o n'which these elements are supported. i

On the shaft 91 is an arm 85. i This is conv nected by' link 88 with astud 86 on the pumpv 81. Thls pump is of the` goose-neck? type, providedwith a nozzle 82 and locatedv within g the melting pot and normallybelovvr th'ejglevel of metal therein so that it will till by gravitypair of brackets 87 extendingupwardly troni the melting. furnace'andcarrying a, cross shaft 89. On this cross shaft isfpivoted end of themeltingpot from .above. efV Each bracket 87 carries at' the top aclamp93havj-'fing projecting 'endsbelow extending the ends of thebearing and heldinkp At the .top ofthe pot 81 arein "lugs 104 similar'to the'fclamp 93` 'se'ciiredffabove the' pot. `This cover is providedwith is" adapted to fit in acup#shaped nip P which is directly connectedwith'the `'pip 76' l" Adjacent to this nipple 1097Lar'gguid enteringholes in the cover up tov positionffor operation? Wh happens' the nozzle82 isalso reglstered'i to. av

dem@

' opening rest or bearingilOl ya lprojection 102 fixed to, or cast"integral with, 'matic pump 81.' This .arrangement 0f :the

parts 91, 89 and 100, together with the loca-v the pneu# e pneumaticpump 81 'from the filling in which it is "verticallybelovv it as shown.The valves arein positlon to prevent flow v `of airto the'pum thediesbeing open and being heldlopen.- y :the oil in the pipe 47. Now thefirsteffect-not the turning of the vhandle into this position is to open'onevalve in the casingv 46,'tojrelease the oil from in frontof thev piston21. 1 Then the other valve f is opened: to allowthe oil'4 to beI forcedthroughthe pipe; 48 into the cylinder-f be- "hindthe piston@ The resultof this is to i svffrom the Iposition shown inv movefthe pa ostionfshownin Fig. 7 This the slidingplate 13,' 'closes xthdravvsfthe ejectors43'.- The je l Q1 ibrW-ardly through f the 'wofthc constructionformf edO *thearm and vthe link 88 and -forces ingin-ftheplate 11;Vv lAt thesame time the Terankfj51, having now reached the'bottom, y the notch'6'Zwil 1. have come" into re ister inf 1*`ig 1'5zinto that shown in Fig.16.VA Now the handle- 6&011 the shaft 68 1 s turned -to tothe pneumaticpump 81v at thetop as will bernbvlous.' New the 'metal is forced vinto'e inoldabyftheair. The parts are left in "thifsjconditioni al very`short period, just long h- Vfor the castingto chilli and retain n thepump I and then exhausted. aving 4been accom lished, the crank oitsoriginal position. This results opposite action of the valvesinthe 16;'fsoj as 1 to' release the bi1. from the l f 4the pistonin` thecylinder-20. 1I,- medi elyj.; the v4'otlier-yvalve f changes andjisforcedthough the pipe 4T to ci le' bringjthis-shaft-around. Thisadmits air i 110,

l jfl'henthe'handle 64 is turned back, he air released .from the top` of,the

s turned 4thei rest -f t e way around' the au racl-iffrvrard actuilsesl` ingltuepum 1 upwar y.

ward limit of its stroke,

the nozzlef82`directlyfinto'the spruevopen.-

10's i l withz'the notch 70,from the positions own. Y

M'wackkthe'w kiston. This .restores the n? .pait'stothe position shownin Fig. 6 and-it will be lseen that the: ejectors 43, although drawn"back slightly, are not drawn bapk a'.s j n`iui 2l1asthe plate 13.Therefore thev castbodily under the control of the handle 51' and thelocation of the several points of support and connections which havebeen shown. It is forced to assume the different positions in proper sequence/ without any attention on the part of the operator except tooperate the handles 51 and 64. The castlug is released from the mold onaccount of the arrangement of the nozzle of the pump and the ejcctingdevices which have been described in full. This ejection is not left to,chance but is made positive by theejectors which will force it out, eventhough therel might be something to cause it otherwise to stick. Thewhole operation is very simple and the machine'itself is reducedl to asmall number of parts and yet has all the safety features which arenecessary in these machines. j

Although I have illustrated and described only a single form of theinvention I am aware of the fact that modications can be made therein byany person skilled in the art without departing from the scope of theinvention as expressed' in the claims.

Therefore, I do not wish to be limited to all the details ofconstruction herein shown `and described," but what Ido claim is L In adiecasting machine, the combination with a piston and cylinder, of anoil pump, two outlet pipes from the oil pump, a pipe extending to eachend of said cylinder for conducting the fluid to operate the piston, avalve casing to which all of said pipes extend, a shaft in said valvecasing, means for connecting` one pairv of pipes with f the other pairso that the oil can be supplied to either end of the cylinder foroperating the piston and there will be no chance for it to enter bothends at the same time, and a handle on the shaft for oscillating it.

2. In a die castin machine, the combination with a pair of dies andmeans for operating the dies comprising a double rack and gear segmentson the opposite sides of the rack, a slide lconnected with said gearsegments for reciprocation to operate one of the dies, and vguides onsaid slide for receiving the rack and guiding it to move in arectangularmanner. l

3..The combination with a pair of dies and a rod, of means forreciprocating said rod, of a double rack adjustablyr fixed on the rod, apair of gear segments on opposite i sides of the rack, meshingtherewith,- and each pivoted vat a stationary point, levers pivotallyconnected with the segments, a link pivoted to the other end of eachlever .anduto 'one die,-a head freely slidable and having an ejector forejecting a casting from the mold, said head being pivoted to saidlevers, whereby when the rod is with- "drawn the head will be withdrawnbut at a slower rate so that the ejectors will project further and ejectthe casting'.

4:.- In a die casting machine, the combination with a-pair of dies, anejector for the casting, and means for operating the dies comprising adouble rack and gear segments on the opposite sides of the rack, a slideconnected with said gear segments for reciprocating one of the dies andejector, another rack fixed with respect to said slide, a. gear meshingwith the last-namedv rack and adapted to turn on a stationary axis andhaving an arm projecting from its shaft, a pumpfor supp ying the dieswith metal, and means operated by said arm for operating the pu'mp.

5.- In a die casting machine, the combination with a pair of dies andmeans for op-` erating one of them, of a rack connected to and 'mevablewith one die when it is operated, a gearmeshing with said rack, anadjustable link connected with said gear to be reciprocated thereby asthe ear oscillates, a pump for` supplying the dles with molten metal,and means operated by said link for moving the pump bodily up to castingposition.

6. In a pump for a die casting machine, the combinationl with a meltingpot, of a pump body adapted to be submerged in the metal of `the meltingpot for filling the pump, means for moving said pump bodily,

said pump having a horizontal nozzle for delivering to the dies in ahorizontal direction a second nozzle above, and a stationary platehaving a metal receiving gland for receiving the lower nozzle anda xedni ple connected with a compressed `air supp y for receiving the secondnozzle so that air can be admitted to the pump over the metal therein,the two nozzles being adapted to come to their two seats simultaneouslyas the pump moves up to casting position.

n a pump for a die casting machine1 the combination with a meltingpot,of a pump body adapted to be submerged in the metal of the melting potfor filling the pump and heating it, means for reciprocating and rockingsaid'pum'p with a motion that will dip it in the molten metal and lillit through its nozzle and bring it up out of the metal for delivery,said pump having a nozzle for delivering to the dies, and a secondnozzle above, a nipple connected with a compressed air supplyv forreceiving the second nozzle so that-air can be admitted to the pump over`ther molten metal, the two nozzles being adapted to come to their twoseats simultavneously as the pump moves up tov casting tposition, aplate on which one member of a ypair of dies ismounted, said platehaving anl o ening for receiving the metal delivery nozz e, and agland-in said opening, the nipx the combination with 'a' melting pot, ofa' l plev also being supported 4in fixed position on said plate.

8.` In a pump for a die casting I'nachinc,

' Vpump body adapted to be submerfgled in the Vmetal of the meltingpotfor pumpand"heatingit, a cover for the pump,

ling the means forreciprocating said pump with a motion that will dip itin the molten metal and then fill it and bring it up out ofthe metal fordelivery,v said pump having a nozzle'for deliverin to the diesand asecond nozzle above, a mpple connected with a compressed ai'r supply forreceiving the second nozzle so that air can be admitted to the pump,-the two nozzles Abeing adapted to come-to their two seatssimultaneouslyas `the pump moves'up to casting position, horizontalguide rods carried by said plate ad- Ajacent tosaid nipple adapted`to'engage the. i

top of the pump for gulding both nozzles horizontallyginto properposition, and means for'clamping the cover onthe pump.

9.. In a` pump for delivering molten metal,

the combination with `a melting pot,of a

pump body located therein, means for vmovner inwhich it is free toreciprocate to compensate for contraction `and expansion of4 theparts-'of the device;

In testimony whereof I. have hereunto aixed my'signature.

' NATHAN LESTER.

40 a support for said'shaft, and means on .the vfurnace for carryingsaid support in aman-

